Excavation cutting tool assemblies for such applications as continuous mining or road milling typically comprise a cutting tool, sometimes referred to as a cutting bit, rotatably mounted within a cutting tool holder, sometimes referred to as a cutting tool sleeve, bit holder, or bit sleeve. In such assemblies, the cutting tool holder is mounted within a support block. The support block in turn is mounted onto a drum or other body, typically by welding, which in turn is driven by a suitable power means. When a number of such support blocks carrying cutting tool holders and cutting tools are mounted onto a drum or other body, and the drum or other body is driven, the cutting tools will engage and break up the material which is sought to be mined or removed. The general operation of such mining, road milling, or other such machines is well known in the art.
As mentioned, the cutting tool holder may be mounted within the support block, typically via some mechanical connection. For example, U.S. Pat. No. 5,322,351 to Lent (referred to as the Lent patent) discloses a cutting tool holder 42 mounted within a tool holder receiving pocket 28 of a support block, referred to in the Lent patent as a segment member 18, via a wedge member 46. The wedge member 46 is movably connected to the support block via an adjustable screw member 54. To use the apparatus disclosed in the Lent patent, a cutting tool holder 42 is disposed in the tool holder receiving pocket 28 such that the base portion of the tool holder mates with, and is located under, an inclined wall surface 24 within the receiving pocket 28. The wedge member 46 is then moved by tightening the adjustable screw member 54 such that the cutting tool holder 42 is held in place by the wedge member 46 and the inclined wall surface 24 of the receiving pocket 28 within the receiving pocket 28 of the support block.
As another example, U.S. Pat. No. 5,378,050 to Kammerer and Diessner (referred to as the Kammerer patent) discloses a chisel holder 30 having a neck 31 which may be inserted into a plug-in receptacle 21 of a support block, referred to as a basic part 20 in the Kammerer patent. The plug-in neck 31 has a recess 37 which defines a pressure surface 38. The pressure surface 38 faces a pressure screw 50 adjustably disposed in the support block, the basic part 20, so as to intersect the plug-in receptacle 21. The pressure screw 50 may be adjusted such that the pressure screw 50 protrudes into the recess 37 of the neck 31 of the chisel holder 30 and such that a retracting force is exerted on the pressure surface 38 of the chisel holder 30.